Ill give you an example by linking you to the most popular and now vastly outdated Locational damage mod found on the Nexus. Depending on what you've done in that save recently as in fighting lots of large battles, it would only take a matter of a few hours for that save game to be unusable as the scripts are lagging drastically behind. That's a big problem as it can quickly bloat a save game and cause a lot of script lag. The main problem was that in order to replicate location based damage, the mods had to use a lot of scripting and it was on a per NPC basis. There have been past attempts at implementing such a system but Skyrim's game engine does not handle locational damage very well.
I would not recommend any kind of locational damage mod to be used for Skyrim if you want to have a stable game.
